Monitoring blood donors for HIV-2 infection by testing anti-HIV-1 reactive sera.

Anti-HIV-1 EIA tests currently used for screening blood donors in the United States are estimated to detect 55 to 91% of HIV-2 infections; Western blots for HIV-1 antibodies may be positive, negative or indeterminate with HIV-2-positive sera. We reasoned that we could exploit the cross-reactivity of the anti-HIV-1 EIA as a means to monitor the blood supply for the appearance of HIV-2 infected or co-infected persons, and thus decide if and when routine HIV-2 screening should be adopted. We tested 913 anti-HIV-1-reactive donor sera using an anti-HIV-2 screening EIA, with confirmation by an anti-HIV-2 env-peptide EIA and an anti-HIV-2 Western blot. These 913 sera were derived from anti-HIV-1 screening of approximately 242,000 donations over a three year period. No HIV-2 infections were identified. This approach may warrant adoption in blood centers serving populations with persons from countries where HIV-2 is prevalent.